Insurgents hijacked a bus near the southwestern town of Mach, killing 13 passengers, a Pakistani police officer told Efe Tuesday.

"The terrorists attacked a frontier guard checkpoint late last night, killed one officer and then stopped a small bus and kidnapped its 20 passengers," Mohammed Iqbal said.

On Tuesday morning, police found the bodies of 13 of the passengers shot to death in a ditch, while the other seven people "are safe and sound," Iqbal said.

Mach is located about 50 kilometers (31 miles) south of Quetta, the capital of Baluchistan, Pakistan's largest and poorest province.

Bordering on Afghanistan, the province is a region where secessionist groups, as well as armed Islamist groups and organized criminal networks, stage regular attacks.

Baluchistan was the province most severely affected by terrorism last year, with 474 incidents of various kinds that resulted in the deaths of 631 people, according to a report by the Pakistan Institute of Peace Studies. EFE